Gastrin Exerts Pleiotropic Effects on Human Melanoma

The effects of gastrin (G17) on the growth and migra-tion factors of four humanmelanoma cell lines (HT-144, C32, G-361, and SKMEL-28) were investigated. The expression patterns of cholecystokinin (CCK)A, CCKB, and CCKC gastrin receptors were investigated in these cells and in seven clinical samples by means of reverse transcription polymerase chain reaction. Melanoma cells appear to express mRNA for CCKC receptors, but not for CCKA or CCKB receptors. Although gastrin does not significantly modify the growth characteristics of the cell lines under study, it significantly modifies their cell migration characteristics. These modifications occur at adhesion level by modifying the expression levels of Av and B3 integrins, at motility level by modi-fying the organization of the actin cytoskeleton, and at invasion level by modifying the expression levels of matrix metalloproteinase 14. We recently demonstrated the presence of CCKB receptors in mouse endothelial cells involved in glioblastoma neoangiogenesis. Chronic in vivo administration of a selective CCKB receptor antagonist to mice bearing xenografts of human C32 melanoma cells significantly decreased levels of neo-angiogenesis, resulting in considerable delays in the growth of these C32 xenografts. In conclusion, our study identifies the pleiotropic effects of gastrin on melanoma cell biology